phpBookingCalendar is an easy to use online booking calendar based on php and MySQL. The calendar is suitable for many non-commersial booking purposes such as booking student or sport facilities, tools, equipment, meeting rooms, apartments, etc... To prevent bots or robots from filling your calendar a captcha is required for every booking and cancellation. To protect the calendar from unauthorized observation or booking, security based on .htaccess and .htpasswd can be implemented.